I have been a casual Linux user since Slackware 3.0 (Hello Walnut Creek!) and an Ubuntu user since around version 6.06 or 6.10.

My primary professional skill set has been focused on the design, implementation, operation, and daily management of enterprise networks.

This includes the configuration and operation of network hardware as well as the care and feeding involved in the network monitoring systems supporting them.
The hardware includes routers, switches, firewalls, wan-optimizers, and occasionally load balancers (mostly Cisco, Riverbed, and f5 systems).